This Slide include the content of Basics of Electric drives, Stability, Different Load effect, Dynamics of Linear and Rotational motion, DC Motor control using single and three phase Full converter (Condition for continuous and Discontinuous Conduction) and Semi converter. DC Motor control using chopper

1. Electric Drives and Control
By
Dr Rajin M. Linus
Associate Professor and HOD
Electrical Engineering Department
Sanjay Ghodawat University,
Kolhapur
Unit-1
Introduction and Basics of Electric Drives

2.  Students will be able to explain2 the characteristics of all electrical
machines
 Students will be able to illustrate2 the speed control of electrical machines
 Students will be able to analyze4 the speed control of electrical
Course Outcome
 Students will be able to classify2 different application of Electric drives and
control
 Students will be able to compare2 different load and its effects on Electric
drives
Unit-1 Outcome
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
2

3. Why We need to Study Electric Drives
Electric Train Lift Escalators Vehicle
Industries Water Pumps Fans Mixer & Grinder Clock
Drilling MachineGrass Cutter 14/01/2020
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
3

4. Why We need to Study Electric Drives Contd…
Wind Energy Conversion
System
Solar Energy Conversion
System
Hydro Electric Power
Generation
Thermal Energy Conversion System
14/01/2020
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
4

5. What is Electric Drives
M/G
Power
Modulator
Source
M/G
Power
Modulator
Source
Control Unit
Sensing
Unit
Block Diagram (Open Loop)
Block Diagram (Closed Loop)
14/01/2020
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
5

6. Power Modulator
Power
Modulator
Diode Rectifier
Fixed AC Fixed DC
Power
Modulator
Controlled Rectifiers
Fixed AC Variable DC
Power
Modulator-I
Tap changer/ AC
Voltage Controller
Fixed AC
Variable
Voltage AC
Power
Modulator-II
Diode Rectifier
Variable
Voltage DC
Power
Modulator-I
Diode Rectifier
Fixed AC
Fixed
Voltage DC
Power
Modulator-II
Chopper
Variable
Voltage DC
Power
Modulator
PWM Inverter
Fixed DC
Variable
Voltage,
Variable
Frequency
Power
Modulator
Cyclo Converter
Fixed
Frequency
Variable Voltage,
Variable Frequency
14/01/2020
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
6

7. Electrical Machines
 AC Brushless Motor
 DC Brushed Motor
 DC Brushless Motor
 Linear Motors
 Servo Motor
 Stepper Motor
14/01/2020
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
7

8. Torque Equation
Motor Load
Torque (T) Load Torque TL
Speed (ωm)
Equivalent Motor - Load System
dt
dJ
dt
d
JJ
dt
d
TT m
m
mL 

  )( ……………………(1)
 (1) is applicable to variable Inertia Drives – Mine Winders, Reel Drives, industrial robots
 For drives with constant inertia 0
dt
dJ
dt
d
JTT m
L

 ……………………(2)
Polar Moment of Inertia of Motor
Load System referred to Motor shaft, kgm2
Instantaneous angular velocity
of Motor shaft, rad/sec.
Dynamic Torque
( Present only transient operations)
Acceleration Deceleration
0
dt
d m 0
dt
d m
0
dt
d m
Equilibrium
Motor Supply Load Torque and
dynamic component
( Eg: Electric Train)
Dynamic Torque Stored in the form
of kinetic energy
Assist T and maintain drive motion
by extracting stored kinetic energy
2
2
1
mJ
14/01/2020
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
8

9. Four Quadrant Operation of Electric Drives
m
T
III
III IV
m
T
Forward
Motoring
Forward
Braking
Reverse
Motoring
Reverse
Braking
m
T
m
T
TL2
TL1
Loaded
Cage
Empty
Cage
Empty
Cage
Motion Motion
Motion
TL
T
m
T
TL
m
TL
T
m
TL
T
m
Motion
Loaded
Cage
Counter
weight
16/01/2020
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
9

10. Components of Load Torque
Load Torque
Friction Torque (TF)
Windage Torque (TW)
Due to Friction present in shaft and
various parts of Load
Torque required for useful
Mech. Work (TL)
Wind generates a torque opposing
the motion
Friction Torque (TF)
FT
m
Components Friction Torque (TF)
T
m
VT CT
CT
ST
ST
Viscous Friction
mB
Column Friction
2
mC
Station or static
friction
ST -Will not be considered for dynamic analysis
2
mcmLl CTBTT  
WT
16/01/2020
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
10

11. Classification of Load Torque
m
lT
2
mlT
Water in Centrifugal Pump, Ship
Propeller
m
lT
High Speed Hoist
m
lT
Traction Load
m
lT
Constant Power Load
Active Load Torque Passive Load Torque
Has a potential to drive the motor
under equilibrium
Eg: Gravitational Force, Tension ,
Compression and Torsion
undergone by elastic body
Eg: Friction, Windage, Cutting etc.
Always oppose the motion and
change their sign on the reversal of
motion
20/01/2020
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
11

12. Loads with Rotational Motion
Motor Load
Load Torque Tlo
Speed (ωm)
Torque (T)
ωm1Jo
Speed (ωm)
Load Torque Tl1
J1
n
n1
Gear
Gear Ratio
1
1
1
n
n
a
m
m



Kinetic Energy 2
11
2
0
2
2
1
2
1
2
1
mmm JJJ  
2
1
2
10 )(
2
1
mJaJ 
[ Losses in Transmission Neglected]
Power Equation
1
11


 ml
mlomL
T
TT  Transmission Efficiency of Gear
1
11

l
loL
Ta
TT 
If m loads with gear a1, a2,….am & Moment of Inertia J1, J2,…..Jm Then,
mm JaJaJaJJ
2
2
2
21
2
10 ........... 
m
lmmll
loL
TaTaTa
TT

 .....
2
22
1
11
20/01/2020
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
12

13. Loads with Translational Motion
Motor Load
Load Torque Tlo
Speed (ωm)
Torque (T)
Jo
Speed (ωm)
Rotational To
Linear Motion
Mass
M1
Force F1
1v
M1 in Kg
v1 m/sec
[ Losses in Transmission Neglected]
Kinetic Energy 2
11
2
0
2
2
1
2
1
2
1
vMJJ mm  
2
1
10 






m
v
MJJ

Power
1
11


vF
TT mlomL 
Transmission Efficiency of Gear







m
ll
vF
TT

1
1
1
0
For m no. of load
22
2
2
2
1
10 .......... 


















m
m
m
mm
v
M
v
M
v
MJJ




















m
m
m
m
mm
ll
vFvFvF
TT

........2
2
21
1
1
0
20/01/2020
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
13

14. Steady State Stability
21/01/2020
m
Torque
T
LT
A
Concept of deceleration
At any Increase in Speed
m
Torque
T
LT
A
Concept of acceleration
At any Decrease in Speed
m
M
m
L
d
dT
d
dT

 m
M
m
L
d
dT
d
dT


Stable System
m
Torque
LT
T
B
Motor Accelerate further
At any Increase in Speed
m
Torque
LT
T
B
Motor decelerate further
At any Decrease in Speed
Unstable System
m
L
m
M
d
dT
d
dT

 m
L
m
M
d
dT
d
dT


Movement of
operating
point
Movement of
operating
point
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
14

15. Steady State Stability Contd….
m
Torque
T
LT
C
Unstable
m
Torque
1LT
A- Unstable
A
B
C
D
T
2LT
B- Stable D- Unstable
C- Stable
21/01/2020
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
15

16. Motor Duty
T
Time (t)
Continuous Duty
Constant Motor Loss: Paper Mill
Drives, Compressors, Conveyers,,
Centrifugal Pumps and Fans
T
Time (t)
Short Time Duty
Less than heating time Constant:
Crane, drives for household
applications, Valve Drives, Sluice –
Gate Drives
T
Time (t)
Intermittent Periodic Duty
Pressing, Cutting and Drilling Machine

Time (t)
Time (t)

24/01/2020Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
16

17. Motor Duty Contd…
T
Time (t)
Intermittent Periodic Duty with Starting

Time (t)
Running
Starting
Rest
T
Time (t)
Intermittent Periodic Duty with Starting and
braking

Time (t)
Running
Starting
Rest Braking
1. Continuous Duty with intermittent Periodic Loading
2. Continuous duty with starting and breaking
3. Continuous duty with periodic speed changes
24/01/2020
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
17

18.  For Continuous Duty
Determination of Motor Rating
 Determine- maximum continuous Power demand
 Next higher power rating Motor – will be selected
 Motor speed should match load speed
 Motor fulfil the starting torque requirement
 Continue to drive load in normal disturbances
 Assure transient and steady state reserve torque capacity
24/01/2020
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
18

19. Determination of Motor Rating Contd….
 For Fluctuating and Intermittent Loads
1. Equivalent Current Method
I
Time (t)
IMax
I1
I2
I3
I4
I5
In
t1 tnt3 t4
t5
t2
Motor Loss p1
Constant Loss pc
Independent of Load
consists Core loss,
Friction Loss
Load dependent
Copper Loss
Fluctuating load has n
values of motor currents
n
nnccc
eq
ttt
tRIptRIptRIp
RIp



.........
).........()()(
21
2
2
2
21
2
12
n
nn
n
nc
eq
ttt
RtItItI
ttt
tttp
RIp






....
)....(
....
)....(
21
2
2
2
21
2
1
21
212




T
n
nn
eq dti
Tttt
tItItI
I
0
2
21
2
2
2
21
2
1 1
......
..........
24/01/2020
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
19

20. Determination of Motor Rating Contd….
 For Fluctuating and Intermittent Loads
2. Equivalent Torque Method




T
n
nn
eq dttT
Tttt
tTtTtT
T
0
2
21
2
2
2
21
2
1
)(
1
......
..........
- T is proportional to current
3. Equivalent Power Method - For fixed speed, P is proportional to Torque




T
n
nn
eq dtp
Tttt
tPtPtP
P
0
2
21
2
2
2
21
2
1 1
......
..........
 For Short time and Intermittent Periodic Duty – Assignment or H/W
24/01/2020Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
20

21.  Students are advised to go through the detailed analysis related to stability with
respect to load and Motor torque characteristics.
 Students are advised to understand the problems and improve the problem
solving skills related to rotational and translational motion in order to improve the
knowledge related to the different types of motion and effects
Information to Students regarding Unit-1
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
21

22. Electric Drives and Control
By
Dr Rajin M. Linus
Associate Professor and HOD
Electrical Engineering Department
Sanjay Ghodawat University,
Kolhapur, Maharastra, India
Unit-2
DC Motor Drives
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
22

23.  Students will be able to explain2 the characteristics of all electrical
machines
 Students will be able to illustrate2 the speed control of electrical machines
 Students will be able to analyze4 the speed control of electrical
Course Outcome
 Students will be able to explain2 different speed control strategy of DC
Motors
 Students will be able to compare2 application of different AC to DC and
DC to DC converters operation in DC Motor Control
Unit-2 Outcome
Dr Rajin M. Linus, Sanjay Ghodawat University, Kolhapur, Maharashtra, India
23

24. Review of DC Motor
 Separately Excited DC Motor
Field and Armature – Independent Control
 Shunt Motor
Field and Armature – Common Source
31/01/2020
M
+
-
VDC VDC
+
-
A1
A2
F1
F2
Separately Excited DC Motor
MVDC
+
A1
A2
F1
F2
Shunt MotorDr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
24

25. Review of DC Motor Contd….
 Series Motor
1. Field and Armature – Current are same
2. Hence, field flux is function of armature flux
 Cumulatively Compound Motor
1. MMF of series field is function of armature current
2. MMF of series field is same direction as MMF of shunt
field
31/01/2020
-
VDC
+ S1
S2
Series DC Motor
Cumulatively compound Motor
M
A1
A2
VDC
+ S1
M
A1
A2
S2 F1
F2
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
25

26. Steady state circuit & Equation of DC Motor
31/01/2020
-
V
+
Steady state Equivalent Circuit
M
Ra Ia
+
-
meb KE 
 Equation for Back Emf, Terminal Voltage and Torque are
meb kE 
…………………..(3)ae IkT 
…………………..(1)
aab IREV  …………………..(2)
 - Flux per pole
 
T
k
R
k
V
e
a
e
m 2

 
a
e
a
e
m I
k
R
k
V

 
…………………..(5)and
…………………..(4)
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
26

27. Steady state circuit & Equation of DC Motor Contd….
31/01/2020
-
 For Shunt and Separately Excited Motor
mmeb kkE  
…………………..(7)aae kIIkT  
…………………..(5)
aab IREV  …………………..(6)
a
a
a
e
a
e
m I
k
R
k
V
I
k
R
k
V



T
k
R
k
V a
m 2
 …………………..(9)
…………………..(8)
and
2
2
2
2
2
2
2
2/
4
4/
0
k
TR
k
V
T
k
TR
k
V
T
k
TR
k
V
T
k
TR
k
V
T
k
V
T
a
a
a
a
m





m
T
aI
T
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
27

28. Steady state circuit & Equation of DC Motor Contd….
03/02/2020
-
 For Series Motor
af Ik
…………………..(11)
2
afeae IkkIkT  
…………………..(10)
aab IREV  …………………..(6)
fe
a
afe
a
e
a
e
m
kk
R
Ikk
V
I
k
R
k
V



fe
a
fe
m
kk
R
Tkk
V

1
 …………………..(13)
…………………..(12)
and
m
T
aI
T
Series
Separately
Excited
Separately
Excited
Series
Rated Operation
Rated Operation
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
28

29. Starting of DC Motor
 Starting Current
1. Twice the rated current. Some cases 3.5 times
2. For full supply voltage Motor may damage
(Eb=0 at standstill)
03/02/2020
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
29

30. How to Limit High Starting Current
 Starting Current- Limited by
1. Using armature voltage (OR)
2. Variable Resistance Control
03/02/2020
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
30

31. How to Limit High Starting Current Contd…
Fixed Voltage and Variable Voltage Control
03/02/2020
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
31

32. How to Limit High Starting Current Contd…
Speed at Fixed and Variable DC Voltage
03/02/2020
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
32

33. How to Limit High Starting Current Contd…
Current at Fixed and Variable DC Voltage
 Torque in the Motor
1. Torque will reflect with current
03/02/2020
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
33

34. Single Phase Full converter Fed DC Motor
04/02/2020
M
T1
T2
T3
T4
P
N
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
34

35. Single Phase Full converter Fed DC Motor Contd…
04/02/2020
Continuous Conduction Mode Discontinuous Conduction Mode
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
35

36. Single Phase Full converter Fed DC Motor Contd…
04/02/2020
b
a
aaama E
dt
di
LRitSinVv  
For   t
For   t
ba Ev 
…………………..(14)
…………………..(15)
Laplace Transform of (14), Avoid Initial Condition
s
E
sIsLsIR
s
V b
aaaam 

)()(22


    
  



















a
a
ab
a
a
a
ma
aa
b
aa
ma
L
R
ss
LE
L
R
ss
L
VsI
RsLs
E
RsLs
VsI
//
)(
)(
22
22




1aI 2aI
  
 
   





























a
a
a
a
a
a
a
a
m
aa
ma
L
R
s
C
s
BAs
L
R
ss
L
L
R
ss
L
V
RsLs
VsI
22
22
22
221
/
/
)(







Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
36

37. Single Phase Full converter Fed DC Motor Contd..
05/02/2020
  
 
   





























a
a
a
a
a
a
a
a
m
aa
ma
L
R
s
C
s
BAs
L
R
ss
L
L
R
ss
L
V
RsLs
VsI
22
22
22
221
/
/
)(







     222222
&,
aa
a
aa
a
aa
a
LR
R
B
LR
L
A
LR
L
C












22
)()( 

Cs
L
R
ABsCA
L a
a
a

   
 
 



























































Z
e
tSin
Z
V
ti
LRs
LR
L
s
LR
R
s
LR
L
LVti
t
L
R
m
a
aa
aa
a
aa
a
aa
a
ma
a
a
)()(
)/(
)(
1
22
22
2222
1
1









Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
37

38. Single Phase Full converter Fed DC Motor Contd..
05/02/2020
























a
a
a
a
ab
a
a
ab
a
L
R
s
B
s
A
L
R
ss
LE
L
R
ss
LE
sI
/
/
)(2
a
b
a
b
R
E
B
R
E
A  &
Bs
L
R
sA
R
E
a
a
a
b
 )(

































t
L
R
a
b
a
a
a
aa
ba
a
a
e
R
E
ti
L
R
s
R
s
R
LEti
1)(
/1/1
)(
2
1
2


Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
38

39. Single Phase Full converter Fed DC Motor Contd..
08/02/2020
21 aaa III 






















t
L
R
a
b
t
L
R
m
a
a
aa
a
e
R
E
Z
e
tSin
Z
V
ti 1)()( 
t
L
R
m
a
b
a
bm
a
a
a
e
Z
V
R
E
R
E
tSin
Z
V
ti







 2
)()( 
1K Transient due to AC voltage and back EMF
…………………..(14)
   








  






tdEttdSinVV bm
1
0

 bm ECosCosV
V
)()(
0


Discontinuous Conduction
 





 




ttdSinVV m
1
0


Cos
V
V m2
0 Continuous Conduction
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
39

40. Single Phase Full converter Fed DC Motor Contd..
08/02/2020
t
L
R
a
bm
a
a
a
Ke
R
E
tSin
Z
V
ti

 )()( (14) Gives
When , t 0)(  tia 
…………………..(14)
(14)

 Cotm
a
b
eSin
Z
V
R
E
K 





 )(
Therefore (14)    
 Cott
a
bCottm
a e
R
E
eSintSin
Z
V
ti )()(
1)()()( 

For ,  t When  t 0)(  tia 
……..(15)
(15) 0)()( )(






  
 Cotm
a
b
a
bm
eSin
Z
V
R
E
R
E
Sin
Z
V
…………………..(16)
Equation (16) provide by iterative method.
Boundary between continuous and discontinuous conduction is  
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
40

41. Single Phase Full converter Fed DC Motor Contd..
08/02/2020
For discontinuous conduction ,
But ,
Critical Speed is Speed at the boundary between continuous and discontinuous conduction
…………………..(17)
(15) …………………..(18)

 bm ECosCosV
V
)()(
0


T
k
R
k
V a
m 2

T
k
R
k
CosCosV am
m
)()(
)(
2










 








 

1
1
)( 

 Cot
Cot
ma
mc
e
e
Sin
kZ
VR
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
41

42. Single Phase Half Controlled Fed DC Motor
08/02/2020
M
T1
D2
D1
T2
P
N
T
k
R
k
CosV am
m
)()(
)1(
2










   








  






tdEttdSinVV bm
1
0

 bm ECosV
V
)()1(
0


 





 




ttdSinVV m
1
0
)1(0 CosVV m 
  T
k
R
Cos
k
V am
m 2
2
1  


Discontinuous Conduction
Continuous Conduction
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
42

43. Single Phase Half Controlled Fed DC Motor Contd…
08/02/2020
Continuous Conduction Mode Discontinuous Conduction Mode
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
43

44. Single Phase Half Controlled Fed DC Motor Contd…
04/02/2020
Continuous Conduction Mode Discontinuous Conduction Mode
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
44

45. Three Phase full converter Fed DC Motor
10/02/2020
M
T1
T6
T3
T4
R
B
Y
T5
T2
A1
A2
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
45

46. Three Phase full converter Fed DC Motor Contd…
10/02/2020
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
Phase and Line Voltage
Phase and Line Voltage Difference
VYB
VRY
60
VBR
VYR
VBY
VRB
30
46

47. Three Phase full converter Fed DC Motor Contd…
10/02/2020
300
Current of T1 and T4 at α=0o with Resistive Load Current of T3 and T6 at α=0o with Resistive Load
120+ 300
180+ 300
120+180+ 300
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
47

48. Three Phase full converter Fed DC Motor Contd…
10/02/2020Output Voltage and Current for R-Load 100 Ohms
240+ 300
240+180+ 300
Current of T5 and T2 at α=0o with Resistive Load
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
48

49. Three Phase full converter Fed DC Motor Contd…
10/02/2020
Three Phase Voltage and Output Voltage at α=0O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
R- Load
Three Phase Voltage and Output Voltage α=30O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
R- Load
300
300
300
o
30
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
49

50. Three Phase full converter Fed DC Motor Contd…
10/02/2020
Three Phase Voltage and Output Voltage at α=60O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
R- Load
Three Phase Voltage and Output Voltage and Current at α=90O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
R- Load (Discontinuous)
o
60
o
90
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
50

51. Three Phase full converter Fed DC Motor Contd…
10/02/2020
Three Phase Voltage and Output Voltage and Current at α=90O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
RL- Load 100 Ohms, 0.05 H (Discontinuous)
Three Phase Voltage and Output Voltage and Current at α=90O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
RL- Load 100 Ohms, 0.5 H (Continuous)
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
51

52. Three Phase full converter Fed DC Motor Contd…
04/02/2020
Three Phase Voltage and Output Voltage and Current at α=90O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
RLE- Load 100 Ohms, 0.05 H, E =100V (Discontinuous)
Three Phase Voltage and Output Voltage and Current at α=90O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
RLE- Load 100 Ohms, 0.5 H, Eb= 100V (Continuous)
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
52

53.  However, for RLE load discontinuous conduction is very rare
 Output Voltage Equation of Continuous Conduction is (If Line Voltage is Taken as
Reference
Three Phase full converter Fed DC Motor Contd…
3

  t tSinVV mAB 
 








CosVV
tdtSinVV
mo
mo
3
2
6 3
2
3

 


But ,
T
k
R
k
V a
m 2

T
k
R
Cos
k
V am
m 2
3
 


and
,
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
10/02/2020
53

54.  Braking Operation when Firing angle greater than 90 Degree
Three Phase full converter Fed DC Motor Contd…
A at α=120O (Zoomed View Between 0.02 Sec and 0.04 Sec)
RLE- Load 100 Ohms, 0.5 H, Eb= 50 V (Braking)

Motoring
Increasing
Braking
T
m
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
10/02/2020
o
120
54

55. Three Phase Semi or Half controlled converter Fed DC Motor
11/02/2020
M
T1
D6
T3
D4
R
B
Y
T5
D2
A1
A2
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
55

56. Three Phase Semi converter Fed DC Motor Contd..
11/02/2020
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
Current of T1 and D4 at α=0o with Resistive Load 100 Ohm Current of T3 and D6 at α=0o with Resistive Load 100 Ohm
300
120+ 300
180+ 300 120+180+ 300
56

57. Three Phase Semi converter Fed DC Motor Contd..
11/02/2020
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
Current of T5 and D2 at α=0o with Resistive Load 100 Ohm Output Voltage and Current for R-Load 100 Ohms
57

58. Three Phase Semi converter Fed DC Motor Contd..
11/02/2020
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
Three Phase Voltage and Output Voltage at α=0O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
R- Load
300
300
Three Phase Voltage and Output Voltage at α=30O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
R- Load
300
o
30
58

59. Three Phase Semi converter Fed DC Motor Contd..
11/02/2020
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
Three Phase Voltage and Output Voltage at α=60O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
R- Load
o
60
300
Three Phase Voltage and Output Voltage and Current at α=90O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
R- Load (Discontinuous)
o
90
59

60. Three Phase Semi converter Fed DC Motor Contd..
11/02/2020
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
Three Phase Voltage and Output Voltage at α=60O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
R- Load
o
60
300
Three Phase Voltage and Output Voltage and Current at α=90O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
R- Load (Discontinuous)
o
90
60

61. Three Phase Semi converter Fed DC Motor Contd..
11/02/2020
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
Three Phase Voltage and Output Voltage and Current at α=90O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
RL- Load 100 Ohms, 0.5 H (Continuous)
Three Phase Voltage and Output Voltage and Current at α=90O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
RL- Load 100 Ohms, 0.05 H (Discontinuous)
61

62. Three Phase Semi converter Fed DC Motor Contd..
11/02/2020
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
Three Phase Voltage and Output Voltage and Current at α=90O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
RLE- Load 100 Ohms, 0.05 H, Eb=50V (Discontinuous)
Three Phase Voltage and Output Voltage and Current at α=90O
(Zoomed View Between 0.02 Sec and 0.04 Sec)
RLE- Load 100 Ohms, 0.5 H, Eb= 50V (Continuous)
62

63.  However, for RLE load discontinuous conduction is very rare
 Output Voltage Equation of Continuous Conduction is (If Line Voltage is Taken as
Reference
Three Phase Semi converter Fed DC Motor Contd…
)1(
2
3


CosVV mo 
But ,
T
k
R
k
V a
m 2

T
k
R
Cos
k
V am
m 2
)1(
2
3
 


Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
10/02/2020
63

64. Step-Down Chopper Fed DC Motor
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
14/02/2020
M
+
D
A1
A2
CH
-
CH
64

65. Step-Down Chopper Fed DC Motor Contd…
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
14/02/2020
Input DC Voltage 350 V, Switching Frequency 10 kHz, Ra= 100
Ohm, L= 9 mH, Eb =100 V (Continuous Conduction)
DCo
T
DCo
VV
dtV
T
V
ON

 0
1
δ is Duty Cycle -
T
TOn
But ,
T
k
R
k
V a
m 2

T
k
R
k
V aDC
m 2



65

66. Step-Up Chopper Fed DC Motor
Dr Rajin M. Linus, Electrical Dept., SGU, Kolhapur
14/02/2020
M
+
D
A1
A2
CH
-
CH
Output Resistance 200 Ohm. Switching Frequency 10 kHz, Source
Ra= 100 Ohm La= 1.5 mH, Eb =350 V (Continuous Conduction)
 
 
1
1
bo
T
T
bo
EV
dtE
T
V
ON
66